1. Field of the Invention
This invention relates to the copolymerization of conjugated dienes, such as 1,3-butadiene, with alpha-olefins, such as propylene. More specifically this invention involves the copolymerization of conjugated dienes with alpha-olefins in the presence of a novel catalyst composition.
2. Related Prior Art
French Pat. No. 2,047,646 described the copolymerization of butadiene and propylene in the presence of a metal compound such as TiCl.sub.4 and AIR.sub.3 reducing agent in which R is hydrocarbon, and a carbonyl-containing compound. While the general discussion of the invention refers to liquid phase polymerization at temperatures in the range of -100.degree. C to 50.degree. C, the preferred temperature is -40.degree. C to -30.degree. C which is confirmed by the fact that in patentee's 30 working examples, a polymerization temperature of -30.degree.C is used in 24 of these examples and -40.degree. C in four examples. It appears that these low polymerization temperatures are necessary to obtain patentee's optimum results in molecular weight, microstructure and other properties in their copolymers.